we have a cluster with two nodes (e.g. "node A" and "node B"). On this cluster we have already installed and configured a RAC-instance (e.g. instance "inst RAC"). The oracle-release of instance "inst RAC" is 11gR2 - for storage we use ASM.

Now we are supposed to install two single instances on that cluster, too. This is more like a management decision since it will safe hardware- and licence-costs. That are the facts, even if Oracle itself doesn't really recomment that kind of configuration.

Anyway, our idea is to install the single instance "inst A" on node "node A" and the single instance "inst B" on "node B". We believe that this "crossover"-configuration will be a good choice - since, just in case one node fails or struggles, only one instance will not be available.

We will build a development-environment for this kind of configuration - but I'm curious if anybody has already some experiences with this kind of configuration and would like to share those with us.